Brakes

The brakes on the 55S17W were (and still are) very poor, bordering on unsafe. TT30 does not
tow anything, it is not heavily loaded, nor did it run anything other than standard XZY road
tyres for the first 23,000 km. Complaints to Iveco garages about the brakes were shrugged off,
and a letter to Iveco Australia through the Iveco Brisbane office received no response even
though one was promised. A follow-up letter a year later to Iveco Brisbane received no response.

The 55S17W has front disk brakes with solid rotors (even though at the time of purchase,
Iveco claimed ventilated rotors) and rear drum brakes. Brake force is shared between front and
rear using a proportioning valve that is manually adjusted upon delivery according to the
expected load. With a camper on the vehicle the load does not change very much and the valve
setting is never altered.

Not only did Iveco advertise ventilated disk brakes and ABS 8 and EBD, their submission
061RVD02K
dated 18 Jan 2012 to Department of Transport under the Road Vehicle Certification System,
CPA 37140-970901, lists the brakes as ventilated disk brakes (DIV) front, disk brakes (DIN) rear.
This Certification was in place when TT30 was delivered, February 2015.

Iveco then claimed solid disk brakes in front with inferior ABS 5.3 and no EBD systems.
Brochure dated July 2015

In July 2015 Iveco put out a revised brochure. As one Iveco salesman said to me soon after,
the brochure "has been truthified"! The reality is that all along, the vehicle has had solid
disk brakes in front (subject too easily to overheating), drum brakes in rear (inferior
performance) and a primitive ABS system without EBD.

It took until 17 February 2017 (!) for Iveco to submit a revision
061RVD02Ka
listed as CPA 37140-1208661 stating that the brakes are solid disk (DIN) in front and drum brakes
(DR) rear.

Note that there is negligible engine braking with the 55S17W due to the way Exhaust Gas
Recirculation is set up. There is no exhaust brake.

So we have:

the non-ventilated brakes on the 55S17W are dangerous due to poor performance and brake
fade and overheating on long descent applications

the advertising and marketing of the Daily around the time of purchase was misleading

the RVCS was untruthful, and

Iveco Australia knows the factory brakes endanger lives since they are evidently offering
selected customers brake upgrades, even for the current model (which has exactly the same brakes
as mine, just smarter electronics).

Very poor Iveco! You are treating Australians, and me in particular, as mugs.

Front Brakes

The OEM pads are very hard and abrasive. In fact, at 22,000 km I took out the pads and observed
that the rotors were maybe wearing faster than the pads! The pads looked like they had worn
imperceptibly compared with the EBC pads that I replaced them with (see below). The rotors had a
lip of about 0.2 mm each side worn on them. It would appear that the pads would have lasted a very
long time.

I have replaced the OEM pads with EBC DP1294/2 pads obtained from
BHSS in Brisbane. These are softer, wear faster
and should stop the vehicle faster without so much wear on the rotors. The EBC pads also fit the
Iveco Daily 35S13 (2002– ) vehicles, and are 17 mm thick. (EBC DP1294 are 19 mm thick and
apparently are too thick to fit.) The EBC 2010 Catalog, UK and International Edition (see
here) lists Iveco Daily under Fiat Commercial at page
102, with illustrations at page 105.
EBC Brakes Australia Direct lists the
pads as DPC12942 under their Carbon Commercial section for the Iveco Daily 1996-2006 and charges
a premium price!

A 22 mm AF socket spanner, a lot of force, and a brake-pad caliper piston spreader are required
to change the pads. Its an easy job, especially the second time.

Rear Brakes

Rusty, wet, rear brake proportioning valve from TT30 before being "fixed" by BHSS.

TravelTrucks had correctly set up the problematic rear brake proportioning valve so that TT30
did have noticeable braking from the rear shoes. However braking was poor and had to be improved.
BHSS offers a service to "fix" the proportioning
valve so that the rear brakes operate at maximum capability, and to increase the braking force from
the actuating pistons by increasing their diameter.

BHSS disassembled the proportioning valve and found it in poor condition, filled with water and
rusted up: a failure waiting to happen.

BHSS bored out the rear brake cylinders and pressed in stainless steel sleeves, increasing the
diameter from approx. 20 mm to 22 mm (13/16" to 7/8"). New larger pistons were fitted. Therefore
the braking force has been increased by 16%.

A test drive showed a definite improvement in braking performance. ABS would even work upon heavy
braking — something that had not happened to that stage. The rear braking performance has
improved further over time.

BHSS chap at work on the rear brakes proportioning valve.

Old and new pistons for the rear brake hydraulic cylinder.

Rear brake cylinder assembly in position ready for work.

Conversion to Diagonal Split Brakes

Diagonal split brakes mean that instead of both front brakes being on one circuit and the rears
on another, one front and the diagonally opposite rear are on one circuit and the others are on the
second. This is arguably safer if a brake line fails, depending on the design and fluid capacity of
the dual master cylinder.

Importantly, because of the difference in fluid volume required to activate the front brakes
compared with that required to activate the rear brakes, changing to a diagonal split makes the
brakes more responsive — less pedal travel for the same brake piston travel. Instead of one of
the two master cylinders controlling the four large pistons in the front brakes, it now only has to
control two, plus two much smaller pistons in the rear brakes. However, the same pedal pressure as
before is required, and brake overheating and fade continue to be major issues.

As shown in the left diagram, the 55S17W comes with a front-rear split. However, the sketch
on the right, taken from the same workshop manual, shows it as a diagonal split.

Examination of the top of the ABS "electro-hydraulic modulator" (left) shows it marked out for
a front-rear split, not a diagonal split. The rear brake lines go to the front, the front brake
lines go to the rear of the block.

Changing to a diagonal split is easy enough: swap the position of the left front (LF) brake
line with the left rear (LR). The pipes are long enough to do this. The photo on the right shows
the job done.

There is a (small) negative in doing this with the existing dual master cylinder. Since the
chambers are not the same size for the two circuits, if a brake failure occurs there will be a
different residual braking performance depending on which split fails. Better would be a master
cylinder with equal chambers, but we don't have that.

There is one more issue. The ABS has to be told of the change otherwise it might release the brake
on the wrong wheel in a skid and send the vehicle out of control. The pin assignments for the plug
on the side of the ABS unit are shown in this table. We need to swap the wires to pins 6 & 7 (LF)
with the wires to pins 8 & 9 (LR), just as we have done for the brake lines.

I disconnected the battery, removed the front inner guard to the left wheel arch and was then
easily able to remove the ABS plug, take off its cover and locate the white and black wires that
needed to be swapped over. It is very important to be methodical here. Its all too easy to mix up
the wires once cut. Cut one white wire, strip insulation from the end going to the plug, cut the
other white wire and strip insulation from the end going away from the plug. Slip heatshrink over
one wire, solder together and seal the heatshrink.Repeat for the remaining white wires.
Repeat the procedure for the black wires.

The arrow points to the plug on the side of the ABS "electro-hydraulic module".

Cover removed, the wires 6 & 7 need to be swapped with wires 8 & 9.

I could not extract the pins, so had to cut and swap the wires, then solder and cover in heatshrink.

With everything back together, the left brake lines may need bleeding to get any introduced air
out. The nipple on the front requires an 11 mm spanner; that on the back requires a 7 mm spanner.
I found that no air had entered the lines; however brake fluid from the master cylinder reservoir
had drained out over the ABS unit while the lines were disconnected but that is all. This was hosed
off.

Comment

Overall, braking feel has been improved by the modifications. If only it were a lot better and
safer!

ABS Defeat for Off-Road Driving

A modification described here allows me to turn off the ABS
when conditions are appropriate — travelling on loose gravel, sand or snow.